US News

BAM MAN’S COOL IDEA: BLOCK SUN

It’s Star Wars vs. global warming.

President Obama’s science adviser said yesterday the United States is considering extreme measures to defeat global warming — such as shooting pollutants miles above the Earth to block the sun’s rays.

John Holdren said the bizarre step — described by fellow scientists as creating an artificial volcano in the sky — would be used only as a last resort.

But, he told the Associated Press, “It’s got to be looked at. We don’t have the luxury of taking any approach off the table.”

Holdren, who advised Al Gore in making his documentary “An Inconvenient Truth,” has been accused of being an alarmist because he warns that environmental disaster will come much faster than colleagues say.

In his first interview since being confirmed as the president’s top science adviser, Holdren said he is discussing what’s called geo-engineering with administration officials.

Holdren gave no details of the idea to shoot pollution particles into the upper atmosphere.

Other scientists have proposed using balloons, military planes or artillery to seed the sky, more than 60,000 feet above Earth, with millions of tons of sulfur.

The aim is to create a vast cloud that would deflect the sun’s rays and prevent the heat from reaching Earth.

But it would turn blue skies white, and could cause droughts and deplete the ozone layer, according to other scientists.

Holdren also raised another idea — creating artificial trees to suck carbon dioxide out of the air and store it underground.

Scientists have debated for years whether the plan, which could cost hundreds of billions of dollars, would work.

Holdren, a respected Harvard professor, conceded there could be grave side effects, and the plan would not solve all global-warming problems.

But, he said, “We might get desperate enough to want to use it.”

Holdren has warned in the past that parts of Cape Cod and Florida will vanish if temperatures continue to rise.

In the interview, he outlined several “tipping points” that could be fast approaching, such as complete loss of summer sea ice in the Arctic.

andy.soltis@nypost.com